From 5286b50c19677aa56c127409cad2bd2bd2ba2f10 Mon Sep 17 00:00:00 2001
From: Bram Matthys <syzop@vulnscan.org>
Date: Mon, 22 Jun 2015 20:49:40 +0200
Subject: [PATCH] We already set the IP in add_connection, no need to do that
 in check_init again. Fix bug where "insecure link" message was shown despite
 localhost.

---
 src/modules/m_server.c |  2 +-
 src/s_bsd.c            | 71 ++++++++++++++----------------------------
 2 files changed, 25 insertions(+), 48 deletions(-)

diff --git a/src/modules/m_server.c b/src/modules/m_server.c
index 45f7bc06f..2b7cbdd42 100644
--- a/src/modules/m_server.c
+++ b/src/modules/m_server.c
@@ -670,7 +670,7 @@ int	m_server_synch(aClient *cptr, ConfigItem_link *aconf)
 		 * Yeah.. there are still other cases when non-SSL links are fine (eg: local IP
 		 * of the same machine), we won't bother with detecting that. -- Syzop
 		 */
-		if (strcmp(cptr->sockhost, "localhost"))
+		if (!IsLocal(cptr))
 		{
 			sendto_realops("\002WARNING:\002 This link is unencrypted (non-SSL). We highly recommend to use "
 						   "SSL server linking. See https://www.unrealircd.org/docs/Linking_servers");
diff --git a/src/s_bsd.c b/src/s_bsd.c
index acd093d63..93122cea8 100644
--- a/src/s_bsd.c
+++ b/src/s_bsd.c
@@ -680,10 +680,9 @@ void write_pidfile(void)
 #endif
 }
 
-/*
- * Initialize the various name strings used to store hostnames. This is set
- * from either the server's sockhost (if client fd is a tty or localhost)
- * or from the ip# converted into a string. 0 = success, -1 = fail.
+/* This used to initialize the various name strings used to store hostnames.
+ * But nowadays this takes place much earlier (in add_connection?).
+ * It's mainly used for "localhost" and WEBIRC magic only now...
  */
 static int check_init(aClient *cptr, char *sockn, size_t size)
 {
@@ -692,32 +691,8 @@ static int check_init(aClient *cptr, char *sockn, size_t size)
 
 	RunHookReturnInt3(HOOKTYPE_CHECK_INIT, cptr, sockn, size, ==0);
 
-	/* If descriptor is a tty, special checking... */
-#if defined(DEBUGMODE) && !defined(_WIN32)
-	if (isatty(cptr->fd))
-#else
-	if (0)
-#endif
-	{
-		strlcpy(sockn, me.sockhost, HOSTLEN);
-		bzero((char *)&sk, sizeof(struct SOCKADDR_IN));
-	}
-	else if (getpeername(cptr->fd, (struct SOCKADDR *)&sk, &len) == -1)
-	{
-		/* On Linux 2.4 and FreeBSD the socket may just have been disconnected
-		 * so it's not a serious error and can happen quite frequently -- Syzop
-		 */
-		if (ERRNO != P_ENOTCONN)
-			report_error("connect failure: %s %s", cptr);
-		return -1;
-	}
-	(void)strlcpy(sockn, (char *)Inet_si2p(&sk), size);
-
-#ifdef INET6
-	if (IN6_IS_ADDR_LOOPBACK(&sk.SIN_ADDR) || !strcmp(sockn, "127.0.0.1"))
-#else
-	if (inet_netof(sk.SIN_ADDR) == IN_LOOPBACKNET)
-#endif
+	/* Some silly hack to convert 127.0.0.1 and such into 'localhost' */
+	if (IsLocal(cptr))
 	{
 		if (cptr->hostp)
 		{
@@ -726,7 +701,6 @@ static int check_init(aClient *cptr, char *sockn, size_t size)
 		}
 		strlcpy(sockn, "localhost", HOSTLEN);
 	}
-	bcopy((char *)&sk.SIN_ADDR, (char *)&cptr->ip, sizeof(struct IN_ADDR));
 
 	cptr->port = (int)ntohs(sk.SIN_PORT);
 
@@ -780,22 +754,6 @@ int  check_client(aClient *cptr, char *username)
 
 	Debug((DEBUG_DNS, "ch_cl: access ok: %s[%s]", cptr->name, sockname));
 
-#ifdef INET6
-	if (IN6_IS_ADDR_LOOPBACK(&cptr->ip) ||
-	    (cptr->ip.s6_addr[0] == mysk.sin6_addr.s6_addr[0] &&
-	    cptr->ip.s6_addr[1] == mysk.sin6_addr.s6_addr[1])
-/* ||
-           IN6_ARE_ADDR_SAMEPREFIX(&cptr->ip, &mysk.SIN_ADDR))
- about the same, I think              NOT */
-	    )
-#else
-	if (inet_netof(cptr->ip) == IN_LOOPBACKNET ||
-	    inet_netof(cptr->ip) == inet_netof(mysk.SIN_ADDR))
-#endif
-	{
-		ircstp->is_loc++;
-		cptr->flags |= FLAGS_LOCAL;
-	}
 	return 0;
 }
 
@@ -1190,6 +1148,25 @@ add_con_refuse:
 		 */
 		get_sockhost(acptr, Inet_si2p(&addr));
 		bcopy((char *)&addr.SIN_ADDR, (char *)&acptr->ip, sizeof(struct IN_ADDR));
+
+		/* Tag loopback connections as FLAGS_LOCAL */
+#ifdef INET6
+		if (IN6_IS_ADDR_LOOPBACK(&acptr->ip) ||
+			(acptr->ip.s6_addr[0] == mysk.sin6_addr.s6_addr[0] &&
+			acptr->ip.s6_addr[1] == mysk.sin6_addr.s6_addr[1])
+	/* ||
+			   IN6_ARE_ADDR_SAMEPREFIX(&acptr->ip, &mysk.SIN_ADDR))
+	 about the same, I think              NOT */
+			)
+#else
+		if (inet_netof(acptr->ip) == IN_LOOPBACKNET ||
+			inet_netof(acptr->ip) == inet_netof(mysk.SIN_ADDR))
+#endif
+		{
+			ircstp->is_loc++;
+			acptr->flags |= FLAGS_LOCAL;
+		}
+
 		j = 1;
 
 		list_for_each_entry(acptr2, &unknown_list, lclient_node)